[Lava]

I no longer use oBG(2) or oIWD, I believe the mods, I only use EE, so I may be unable to help. However, I noticed the word "palette" in there. Try summoning this creature with the console: L#ASTHU. I believe that there is a chance the creature uses a color that in unavailable in non-EE game. If the game crashes when you summon this creature, it's most likely not the script but the .cre that's using some "illegal" setting.